Upon the addition of 2,4-dinitrophenol (DNP) to a suspension of mitochondria carrying out oxidative phosphorylation linked to the oxidation of malate, what does NOT occur? A) Oxygen consumption decreases. B) Oxygen consumption increases. C) The P/O ratio drops from a value of approximately 2.5 to 0. D) The proton gradient dissipates. E) The rate of transport of electrons from NADH to O₂ becomes maximal.

Question

Quizplus · Accepted Answer

Addition of DNP uncouples electron transport from oxidative phosphorylation by increasing the permeability of the inner mitochondrial membrane to protons, thereby dissipating the proton motive force. As a result, oxygen consumption increases due to the higher rate of electron transport, but there is no change in the consumption of oxygen molecules themselves.

Upon the Addition of 2,4-Dinitrophenol (DNP) to a Suspension of Mitochondria